The Mt. Washington Observatory, where the Big Wind was measured, proudly claims to be ‘Home of the World's Worst Weather.’ It is a private, nonprofit scientific institution, the successor to the U.S. Signal Service, which conducted meteorological observations on Mt. Washington from 1870 to 1892. It was the first weather observatory in the world.
On a clear day, the view from the summit of Mt. Washington stretches 130 miles, to the Atlantic Ocean in the east and Lake Champlain in the west.
P.T. Barnum once climbed Mt. Washington and exclaimed, "This is the second greatest show on earth."
During the winter, the wind speed exceeds 100 mph on about one every three days.
The Abenaki people called the mountain Agiocochook, or 'Home of the Great Spirit.' They believed the gods dwelt at the peak, and didn't climb to it out of deference. In 1642, an Irish ferry operator named Darby Field climbed the mountain. Massachusetts Gov. John Winthrop described Field's climb to the top of the 'white hill' in his journal. "They had neither cloud nor wind on the top, and moderate heat," noted Winthrop.
The mountain sits at the convergence of three storm tracks from the Atlantic Ocean to the south, the southwest and the northwest. Westerly winds accelerate as they race up the mountainside. And low pressure systems develop along the warmer ocean in winter and collide with the colder Northeast air, causing storms to develop.
Because of its severe weather, Mt. Washington is known as 'the most dangerous small mountain in the world.' On that April day in 1934, it was indeed dangerous for the five men hunkered down in the observatory.
The 2-year-old observatory was staffed by Salvatore Pagliuca, Alex McKenzie and Wendell Stephenson. They had two guests, Arthur Griffin and George Leslie. The small building was chained to the ground.
When the men went to bed on the night of April 11, pressure was falling and winds were increasing rapidly to 136 mph. By the next morning it was obvious they were in the middle of a super-hurricane. Stephenson checked the instrument that recorded the wind speed and saw it was wrong. That meant the anemometer was iced over.
Stephenson suited up, grabbed a club and opened the door. The wind knocked him down. With the wind at his back, he climbed the ladder, clubbed the anemometer dozens of times and cleared the ice -- an incredibly difficult and dangerous task. Then he went back into the station and checked the recorder. It showed a windspeed of 150 mph.
The men recorded frequent values of 220 mph, with occasional gusts of 229 mph. Then, at 1:21 pm on April 12, 1934, the extreme value of 231 mph out of the southeast was recorded.
To experience a similar wind, wrote one observer, you'd have to poke your head out of a 747 on takeoff.
The record held until 2010, when a review of climate data turned up a 253 mph gust on Barrow Island in Australia during Cyclone Olivia in 1996.
This story was updated from the 2014 version.